nested CNAMEs resolution failures?

[Tony Finch]

cardenas at sig.com <cardenas at sig.com> wrote:

> Can someone help me understand why I cannot resolve file.caixin.com, but
> if I direct my queries to open resolvers from the likes of
> Google/Verizon they yield positive results?

Good grief, another DNS cookie problem. Weirdly their servers seem to cope
OK with cookies except for this CNAME - e.g. www.caixin.com works and has
a similar CNAME, but file.caixin.com fails.

$ dig +short ns caixin.com | while read s; do dig +short $s a $s aaaa; done
43.242.49.158
43.242.49.158
113.209.232.218

$ dig file.caixin.com @43.242.49.158

; <<>> DiG 9.13.0-dev <<>> file.caixin.com @43.242.49.158
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 33984
;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;file.caixin.com.               IN      A

;; AUTHORITY SECTION:
caixin.com.             60      IN      SOA     bj.gtm.caijingnews.com. hostmaster.bj.gtm.caijingnews.com. 2373 10800 3600 604800 60

;; Query time: 184 msec
;; SERVER: 43.242.49.158#53(43.242.49.158)
;; WHEN: Mon Jan 29 12:38:04 GMT 2018
;; MSG SIZE  rcvd: 110

$ dig +nocookie file.caixin.com @43.242.49.158

; <<>> DiG 9.13.0-dev <<>> +nocookie file.caixin.com @43.242.49.158
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 36216
;; flags: qr aa rd ad; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;file.caixin.com.               IN      A

;; ANSWER SECTION:
file.caixin.com.        3600    IN      CNAME   www.caixin.com.bbdglb.com.

;; Query time: 182 msec
;; SERVER: 43.242.49.158#53(43.242.49.158)
;; WHEN: Mon Jan 29 12:38:21 GMT 2018
;; MSG SIZE  rcvd: 80

Tony.
-- 
f.anthony.n.finch  <dot at dotat.at>  http://dotat.at/  -  I xn--zr8h punycode
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